Patent · US Expired

Key making use of the properties of a liquid crystal

US5043710A · kind A · utility

14Cited by
7References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 5, 1989
Grant dateAug 27, 1991
Priority date
Expiry dateJun 5, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K17/962
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A touch sensor comprises a liquid crystal cell (10) and detector means (40, 50A, 50B) responsive to a change in the dielectric constant of the liquid crystal. The detector means comprise an HF electrical signal generator (40) together with integration means (50A, 50B) suitable for integrating the charge created by any change in the dielectric constant of the liquid crystal (14).

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.